100 Years Old and Full of Vitality – The Secret of Okinawa Island

Yle TV1 Prisma 13 June 2018
BBC – Document “How to stay young”

 

 

How can nutrition affect brain health until old age? On Okinawa Island in Japan, there are only half as many dementia patients in comparison with the rest of the world and one explanation for it may be food. What is it in the food of Okinawans that explains their brain health and long life? Professor Craig Willcox is familiar with the local diet. When examining the centenarians, he found a vegetable he thinks may be the key factor. The Okinawan sweet potato has been a favourite food of the Okinawan people for a long time already. They eat an average of more than half a kilo of this sweet potato a day. Professor Willcox believes that the sweet potato explains in part the low occurrence of dementia among the Okinawans and their risk of heart disease, which is 80 percent lower compared with other populations. The Okinawan sweet potato keeps the blood vessels in good condition. Okinawan seniors feel much better than their Western peers.
Shinpuku Tamakay (in the photo on top) gets plenty of nutrients from his food. The Okinawan sweet potato is his favourite food. “It makes you feel really refreshed,” he says. Mr. Tamakay is a shining role model for ageing people. He is a centenarian who zips around by moped from one place to another. “His diet supports healthy ageing,” observes Professor Willcox. 

 

The Okinawan sweet potato accounts
for most (69%) of the daily diet
of average
Okinawans.

What does the Okinawan sweet potato contain that makes it power food? Doctor Paul Kroon works at the Quadram Institute Bioscience, researching food. He studies compounds, which may explain why the Okinawan sweet potato is so effective. We are looking for specific compounds, called anthocyanins, in certain vegetables. Anthocyanins are the colourants of the cells of these plants and the Okinawan sweet potato gets its colour from them. Doctor Kroon believes that these compounds promote brain health on Okinawa Island. Anthocyanins appear to maintain the flexibility of arteries. When a person ages, the blood vessels harden. This is why blood pressure rises and blood circulates increasingly poorly, whereby nutrients are carried to the tissues less efficiently. Blood circulation is important to the brain, which needs nutrients and oxygen, as well as the removal of various substances from the brain. Anthocyanins keep the arteries flexible, which benefits the brain and other organs in many ways. Anthocyanins may also reduce cholesterol. The Okinawan sweet potato is not widely known. What other foodstuffs have the same effect? Examples include dark grapes and red cabbage and some fruit, as well as berries, including bilberries, blackberries, blackcurrants and strawberries. The anthocyanin content of wild bilberries is particularly high.

Should you add dark vegetables to your diet? If you want to achieve the same level as the people on Okinawa Island, where the Okinawan sweet potato is a staple, you must eat a lot of bilberries, blackberries and blackcurrants. You can also bring more sources of anthocyanins to your diet. Instead of green vegetables, you can take purple ones, pick red apples instead of green ones, and eat blackberries and bilberries instead of pears and bananas. Luckily, you can promote brain and heart health and slow down the ageing of your brain by eating more vegetables, especially the purple coloured ones. 

Craig Willcox
Okinawa International University

Paul Kroon
Quadram Institute Bioscience, Norwich